152P/Helin–Lawrence
Periodic comet
From Wikipedia, the free encyclopedia
152P/Helin–Lawrence is a Jupiter-family comet with a 9.52-year orbit around the Sun. It is the third comet co-discovered by Eleanor F. Helin and Kenneth J. Lawrence.[a][b]
P/2001 Y1
| Discovery[1] | |
|---|---|
| Discovered by | Eleanor F. Helin Kenneth J. Lawrence |
| Discovery site | Palomar Observatory |
| Discovery date | 17 May 1993 |
| Designations | |
| P/1993 K2 P/2001 Y1 | |
| 1993 XI, 1993l[2] | |
| Orbital characteristics[3][4] | |
| Epoch | 9 February 2015 (JD 2457062.5) |
| Observation arc | 31.71 years |
| Earliest precovery date | 21 April 1993 |
| Number of observations | 1,298 |
| Aphelion | 5.874 AU |
| Perihelion | 3.113 AU |
| Semi-major axis | 4.493 AU |
| Eccentricity | 0.30722 |
| Orbital period | 9.52 years |
| Inclination | 9.868° |
| 91.899° | |
| Argument of periapsis | 163.59° |
| Mean anomaly | 97.858° |
| Last perihelion | 13 January 2022[5] |
| Next perihelion | 9 July 2031[6] |
| TJupiter | 2.901 |
| Earth MOID | 2.099 AU |
| Jupiter MOID | 0.338 AU |
| Physical characteristics[3] | |
Mean diameter | 4.6 km (2.9 mi)[7] |
| Comet total magnitude (M1) | 12.7 |
Observational history
Both Helin and Lawrence discovered the diffuse trails of the comet from the photographic plates exposed from the Palomar Observatory on the night of 17 May 1993.[1] At the time, it was a 17th-magnitude object within the constellation Scorpio.[c] Shortly after the announcement of its discovery, Robert H. McNaught was able to observe it during the total lunar eclipse of 4 June 1995.[9]
It was recovered from the Saji Observatory by T. Oribe and Shuichi Nakano on 24 December 2001.[10]
Physical characteristics
Polarimetric observations from the European Southern Observatory in 2012 revealed that both 74P/Smirnova–Chernykh and 152P/Helin–Lawrence still produce cometary activity even at large heliocentric distances, suggesting that both comets were relative newcomers to the inner Solar System and thus contain large reservoirs of volatile material in their respective interiors.[11]
The nucleus of 152P/Helin–Lawrence is estimated to be around 4.6 km (2.9 mi) in diameter,[7] based on observations conducted using the Hubble and Keck telescopes in 1998.[12]